1. Field of the Invention
The present invention relates to a multi-patch antenna, and more specifically, to a multi-patch antenna that can provide two frequency service.
2. Description of the Prior Art
The rapid development of the Internet has allowed data and information to accumulate rapidly, and the circulation and sharing of large amounts of technology and knowledge is becoming increasingly efficient. Recently, developments in wireless networks allow users to access network resources whenever and wherever they want. Information is entering every aspect of our work and our lives. One feature of wireless networks is to remove the cables associated with traditional network infrastructure. Using electromagnetic waves or infrared signals to transfer data between network terminals, users can connect to a wireless network and access network resources. Under wireless network system architecture, all network servers transmit and receive wireless data signals via an access point, and provide network resources and service wirelessly. Similarly, in order to utilize the resources and services provided by wireless networks, the connecting terminals need the ability to transmit and receive wireless data signals. Terminals such as PCs or notebook computers can be expanded to have wireless network functions by installing wireless LAN cards.
The service range and area of a wireless network is largely influenced by the design of an access point. The design of an internal antenna in the access point plays a very important part. If a multi-patch structure is used, the antenna can benefit from the effects of high gain and high bandwidth.
Please refer to FIG. 1, which is an exploded perspective view of a prior art multi-patch antenna 10. The multi-patch antenna 10 comprises a stacked-patch 18, a PCB 30, and a feed line 37. The stacked-patch 18 comprises a first substrate 20, a first filling layer 22, a second substrate 24, and a second filling layer 26 in an arrangement that yields an ability to operate using a wide bandwidth. An upper layer of the PCB 30 comprises a ground layer 28. Below the ground layer 28 is a substrate 32, and below the substrate 32 is a microstrip line 34 electronically connected to the feed line 37 for receiving input radio signals at one end. Further provided is a slot 36 in the ground layer 28 directly beneath the stacked-patch 18 and crossing the microstrip line 34. When multi-patch antenna 10 is required to send out a radio signal, the radio signal is input from feed line 37.
The multi-patch antenna 10 is an application of mature technology. Take for example a 2.4 GHz frequency according to IEEE802.11b, a gain of the antenna 10 can reach approximately 6 dBi to 9 dBi, with a bandwidth that is about 15% above average. The same design principle can also be applied to a high gain antenna conforming to a 5.25 GHz band of IEEE 802.11a. Currently, IEEE 802.11 module chip design has led to an intelligent module that can use either the 2.4 GHz or 5.25 GHz frequencies to communicate with IEEE 802.11b or IEEE 802.11a modules at other access points. But under these circumstances, the multi-patch antenna 10 described above is inadequate. The use of microwave bands is becoming increasingly complicated. For instance, the most general IEEE 802.11 standard currently used for wireless networks has the common 2.4 GHz ISM wave band in IEEE 802.11b and an improved version of the 5.25 GHz in IEEE 802.11b. Furthermore, 5.4 GHzxcx9c5.8 GHz is now in application in a European standard of HyperLan-2. A key reason why we must develop a antenna with the capability to receive and transmit with multiple frequencies is to reduce access point design complexity and cost.
It is therefore a primary objective of the claimed invention to provide a multi-patch antenna with the capability for dual frequency service, fulfilling the need for a single antenna to transmit two frequencies simultaneously.
The multi-patch antenna comprises a PCB and two stacked-patches. The PCB includes a substrate, a metal layer formed on an upper side of the substrate, and a microstrip line formed on a lower side of the substrate. The microstrip line transmits radio signals through two slots above the metal layer, the two slots being covered by the two stacked patches. The radio signals resonate within the two slots and the two stacked patches covering the two slots, and are then emitted from the stacked-patches in a direction normal to the stacked-patches.
It is an advantage that the claimed invention can receive and transmit two frequencies simultaneously.
It is an advantage of the claimed invention that the structure of the multi-patch antenna causes it to be highly unidirectional. It can not only be used in outdoor point-to-point communication, but can also be used indoors as a wall-hanging or ceiling-fastened device. With its high gain and unidirectionality, the claimed invention flat patch antenna design boosts communication quality.
These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.